Like many modern human beings, I keep electronic calendars. I use Google calendar for many of them, but I also have a couple on my Mac, a couple on my iPhone, and the like. I have a calendar for each of my three jobs, for family events, I have shared calendars for groups I belong to, and, of course, Birthday calendars. My Calendar app is a many-colored thing.

But what happens when you just want to see one of these calendars at any given moment? Just birthdays, for example, without cluttering it up with a bunch of job-related stuff? If you use the built-in Mac OS X Calendar app, this is pretty simple. Here’s how to do it.

To hide all other calendars except the one you want to view, hold Command-Option on your keyboard at the same time, and then click on the calendar you want to show. All the other calendars will un-check, leaving just the one you clicked visible in the month, week, or day view.

Want to show all the calendars at once? Hold the Command key down and then click any calendar in the list to the left. Boom! Everything shows up again.